Tire Rotations - Why & When
Tires rotate all the time as they roll down the road, but that's not what it means to "rotate" your tires. Rotating your tires means to move each tire from its original wheel position to another, moving them left to right, back to front, or even diagonally, for the purpose of promoting even tire wear.
Why should your vehicle's tires be rotated? Simple: Tires tend to wear unevenly. The front tires tend to wear on the outside edges because the tire leans when you turn a corner. The rear tires follow the front tires instead of moving independently, so they usually wear more evenly. Failing to rotate your tires means the outside edges on the vehicle’s front tires will wear down much faster than the rear tires, causing them to need replacement thousands of miles sooner than average, and will contribute to your tires needing to be replaced individually or in pairs, rather than as a set. Each wheel position can cause different tire wear rates and different types of tire wear. Proper tire rotation allows each tire to serve in as many of the vehicle's wheel positions as possible, thereby promoting even wear on all four tires, prolonging the life of your tires, and evening out their lifespans.
The usual recommendation for tire rotation is every 3,000 - 6,000 miles. However, the need for rotation will differ among tire manufacturers, vehicle makes, and driving habits.
A vehicle’s weight is distributed differently to the front and rear tires. Engines are most commonly placed in the front end of a vehicle; therefore, the front tires typically bear more weight than the rear tires. Braking and constant steering maneuvers place additional stress on the front tires as well. Tires on front-wheel drive vehicles carry the weight of the engine, as well as the additional weight of the transaxle, which increases the uneven weight. The tires of performance vehicles, vehicles designed and constructed specifically for speed, will also experience more severe tire wear.
Mechanical, suspension, and steering linkage problems may contribute to uneven tire wear. Wheels misaligned with each other and/or with the vehicle's axis will tend to be dragged along by the other wheels, causing uneven wear in that tire. If the alignment is such that the vehicle tends to turn or pull while driving, the driver will correct for the pulling by steering against it, causing the vehicle to be in a constant state of turning which contributes to uneven tire wear.
The tire rotation pattern is typically to move the back wheels to the front, and the front wheels to the back, sometimes crossing them diagonally. If the tires are unidirectional, the rotation can only be rotated front to back on the same side of the vehicle to preserve the rotational direction of the tires.
If tire rotations have been neglected and two of the four tires are nearly worn out, the best tires should be kept at the rear wheel positions of the vehicle regardless of whether the vehicle is front or rear-wheel drive. The reason for this is if the rear wheels lose traction before the front ones, an oversteer condition will occur which is harder to control than the corresponding understeer which will happen if the front wheels lose traction. This is also true in the case of a tire blow out. Consequently, the intuitive belief that the front tires need to be the best quality is not the case. However, if front and rear tire tread depths are close to the same but a little bit different, the best tires should be rotated to the front to help even out the wear on all four tires.
A rear tire blow out will cause the vehicle to become difficult to control, especially if the blow out occurs at highway speeds. The risk of rollover is also increased due to yawing, a condition where the rear of the vehicle swings out and becomes perpendicular to the direction of travel. Yawing will cause the tire to separate from the rim, allowing the rim to dig into the pavement, dirt, or grass if the vehicle is no longer on the road, which will cause the vehicle to rollover.
Have your tires rotated during every 3,000 - 6,000 mile interval oil change. During the rotation, each tire should be inspected for damage. Any stones or debris should be removed from the tire treads. Steering and suspension components, as well as the tread depth of each tire should be inspected. And last but not least, the air pressure of each tire should be inspected and adjusted to optimal levels.
Using tire rotation correctly as a proactive and preventative maintenance measure will equalize front-to-rear and side-to-side wear rates while enhancing total wear quality. Any obvious differences in the wear rates of a vehicle’s front and rear tires is a sure sign that tire rotations should be done more frequently. When your tires wear evenly and wear out together, you will be able to purchase a set of four new tires without being forced to buy pairs, and proper rotation will extend the life of your tires which will save you time and money in the long run.
If you have any question about the condition of your tires, or about why and when they need to be rotated, have an ASE certified technician inspect the tires and components as described above and answer any questions you have.